Automatic tank washer with spin-burst mechanism for washing, rinsing, and sanitizing

ABSTRACT

Portable equipment for automatically washing milk storage tanks comprises a spinning discharge nozzle for the tank, a motor driven pump, a regulating chamber in communication with the pump, solenoid valves for controlling water flow to the chamber, regulating valve system at the bottom of the regulating chamber, and an electric timer and a pressure switch. The regulating valve system comprises a hollow extension at the bottom of the regulating chamber with a drain opening at the bottom thereof, and drain stoppers connected to a stopper rod for closing the drain opening or the opening between the regulating chamber and the hollow extension. A conduit is connected from the bottom of the tank to be washed and a nipple opening in the hollow extension. The timer cams are adapted to provide a cycle of operation which includes a first rinse, a wash, a second rinse and an optional sanitize cycle. At the initial portions of the first and second rinse cycles, the pressure switch and other controls respond to rising and falling water levels in the regulating chamber to effect intermittent operation of the pump to provide spin-burst action of the nozzle inserted in the tank. The pressure switch also effects intermittent operation of the timer during these initial portions of the rinse cycle to enable the timer to advance to the regular portions of the cycles.

United States Patent 1 Bender Apr. 9, 1974 41 AUTOMATIC TANK WASHER WITH SPIN-BURST MECHANISM FOR WASHING, RINSING, AND sANiTiZrNG Lloyd F. Bender, Rt. 5, Hayward, Wis. 54843 22 Filed: Sept. 21, 1972 211 Appl. No.: 290,987

[76] Inventor:

Primary Examiner--S. Leon Bashore Assistant ExaminerRichard H. Tushin Attorney, Agent, or Firm-James E. Nilles [57] ABSTRACT Portable equipment for automatically washing milk storage tanks comprises a spinning discharge nozzle for the tank, a motor driven pump, a regulating chamber in communication with the pump, solenoid valves for controlling water flow to the chamber, regulating valve system at the bottom of the regulating chamber, and an electric timer and a pressure switch. The regulating valve system comprises a hollow extension at the bottom of the regulating chamber with a drain opening at the bottom thereof, and drain stoppers connected to a stopper rod for closing the drain opening or the opening between the regulating chamber and the hollow extension. A conduit is connected from the bottom of the tank to be washed and a nipple opening in the hollow extension. The timer cams are adapted to provide a cycle of operation which includes a first rinse, a wash, a second rinse and an optional sanitize cycle. At the initial portions of the first and second rinse cycles, the pressure switch and other controls respond to rising and falling water levels in the regulating chamber to effect intermittent operation of the pump to provide spin-burst action of the nozzle inserted in the tank. The pressure switch also effects intermittent operation of the timer during these initial portions of the rinse cycle to enable the timer to advance to the regular portions of the cycles.

8 Claims, 5 Drawing Figures to 5:23 wwz E :23 mm;

8 Om cm 2 o 26 PATENTEDAPR 9 I974 SHEET 3 BF 3 mwm AUTOMATIC TANK WASHER WITH SPIN-BURST MECHANISM FOR WASHING, RINSING, AND SANITIZING BACKGROUND OF THE INVENTIO 1. Field of Use This invention relates to portable equipment for automatically cleaning liquid storage tanks, such as milk bulk storage tanks used in the dairy industry, and to a method for operating the equipment to provide rinse and wash cycles with intermittent spin-bursts at the outset of the rinse cycles.

2. Description of the Prior Art My U.S. Pat. No. 3,448,742 issued June 10, 1969 for Portable, Automatic Washing Unit for Tanks" discloses a unit for cleaning milk storage tanks or the like which comprises a spinning discharge nozzle for insertion in a tank, a regulating chamber adapted to be supplied with water from a suitable source through solenoid valves, a motor driven pump for supplying water from the chamber to the discharge nozzle, a solenoid operated drain valve for the regulating chamber, a pressure switch responsive to fluid levels in the regulating chamber, and a timer for controlling operation of these elements to provide rinsing and washing cycles. In this unit, both the rinse water and wash water were recirculated during the appropriate cycles and sprayed in a constant stream into thetank, after which the drain valve opened and the water was drained from the tank.

SUMMARY OF THE PRESENT INVENTION A portable automatic washing unit for tanks in accordance with the invention comprises a support frame, an electric motor driven fluid pump carried on the frame, and a fluid regulating chamber carried on the frame. The regulating chamber is provided with a regulating chamber drain opening at the bottom and with a hollow extension therebelow which terminates in a tank drain opening. A first nipple or fluid port is provided at the lowerend of the regulating chamber above the regulating chamber drain opening. A second nipple or fluid port is provided on the extension intermediate the two drain openings. A'first conduit means or hose'is connected at one end to the discharge end of the pump and has its free end connected to a spinner nozzle which is adapted to be placed in a tank to be cleaned.'A second conduit means or hose is connected at one end to the inlet end of the pump andat its other end to the first nipple on the discharge chamber. 'A third conduit means or hose is connected at one end to the second nipple on the regulating chamber extension and its other end is connectable to the lower portion of the tank; both third hose connections being at a level whereby fluid is able to drain between the chamber and the tank to regulate the fluid level in the tank. Solenoid operated double drain stopper or regulating valve means are provided and comprise a regulating chamber drain stopper engageable with the regulating chamber drain opening and a tank drain stopper engageable with the tank drain opening. Both drain stoppers are mounted on a solenoid operated spring-loaded vertically shiftable rod and, when this solenoid is energized, the tank drain is closed and the regulating chamber drain is opened. Conversely, when this solenoid is deenergized, the tank drain is opened and the regulating chamber is closed. Electrical control means. are provided and comprise an electric timer including a timer motor and four cams; a solenoid operated mixed (hot and cold) water supply valve and a solenoid operated hot water supply valve, both for supplying water to said regulating chamber; water level regulating means extending into the regulating chamber and including a pressure switch; a pump motor controller including a contactor coil; and a solenoid for operating the aforesaid drain stopper means.

In its method of operation, the unit provides a first rinse cycle (of, for example, 6 minutes), a wash cycle (of, for example, 14 minutes), a second rinse cycle (of, for example, 10 minutes), and an optional sanitize cycle (of, for example, 12 minutes); with each cycle programmable for a desired interval of time. The initial portions (of, for example, one minute each) of thefirst and second rinse cycles are spin-burst cycles when the regulating chamber alternately fills and empties as the pump alternately operates to provide spin-burst spray action in the tank. During all portions of the two rinse cycles, rinse water drains from the tanks and is discharged. During the wash cycle, detergent-laden water is recirculated and reused before being drained from the tank and discharged near the end of the cycle. During the sanitize cycle, chemical-laden water is recirculated and reused before being drained from the tanks and discharged.

A washing unit in accordance with the invention provides numerous advantages in construction and mode of operation over prior art apparatus. For example, the solenoid operated double drain stopper means for the regulating chamber and tank enables convenient and economical discharge of rinse water during the rinse cycles and conservation of hot, treated water during the wash and sanitize cycles. Furthermore, the electrical control means enables highly efficient spin-burst cycles at the start of the rinse cycles without departing on a more complex and costly timer mechanisms to provide such cycles, which in the invention are provided by pressure switch action and the design of the regulating chamber. Other advantages and objects of the invention will hereinafter appear.

DRAWINGS FIG. 1 is an elevational view of a unit in accord nce with the present invention being used in clean g a tank, with certain parts being shown as broken a ay, in section or removed for clarity in the drawings;

FIG. 2 is a plan view taken along line 2-2 of FIG. 1, with certain parts being shown as broken away or removed for clarity;

FIG.'3 is an elevational view, with portions broken away, of the regulating chamber shown in FIG. 1 with the stoppers therein shown in another position;

FIG. 4 is a diagram of an electrical circuit used in the present invention; and

FIG. 5 is a time chart showing the various functions and cycles that occur during operation.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 and 2, the unit U includes a support frame F fabricated from steel tubing, or the like,

I which is welded together and provided with castor wheels 1 for easy portability. A control box 2 is rigidly supported on the frame and has a pair of water hoses 3 and 4 extending therefrom for detachable connection to conventional spigots (not shown), respectively, of conventional cold and hot water lines which furnish the necessary water. Also supported on the frame is a conventional electric motor driven fluid pump P of the impeller type having its outlet connected to a conduit 5 for delivering the water to the upper side ofa tank 6 to be Cleaned. The inlet of the fluid pump is connected by a conduit 10 to a nipple 11 in the lower side of a regulating chamber C also carried on the frame.

The regulating chamber C is generally cylindrical in shape, upright and may be open at its top. Chamber C is provided at its lower end with a generally cylindrical hollow extension 13 having a regulating chamber drain opening 40 at its upper end and a tank drain opening 41 at its lower end. The sides of the openings 40 and 41 form valve seats for vertically shiftable valve elements in the form of a regulating chamber drain stopper 42 and a tank drain stopper 43, respectively. The bottom of chamber C is provided with a drain hole 44.

The drain stoppers 42 and 43 are connected to the lower end of a stopper rod 14a that extends centrally down into the chamber. The stoppers 42 and 43 are conical in shape and may be of resilient material for good seating, such as rubber. Each stopper is also adjustable on the rod by a threaded connection therewith. The rod is vertically shiftable in a bushing 14b fixed by a lock nut 140 to the bottom of the control box. A spring 14d biases the rod downwardly. The rod 140 is raised by the action of the electric solenoid 14e connected to the top end ofthe rod. The drain solenoid Me is energized by a timer T.

When rod 140 is raised by energization of solenoid 14c, stopper 42 is raised to open regulating chamber drain opening 40 and stopper 43 is raised to close tank drain opening 41, as FIG. 3 shows. When rod 14a is lowered by de-energization of solenoid 142, stopper 42 is lowered to close regulating chamber drain opening 40 and stopper 43 is lowered to open tank drain opening 41, as FIG. 1 shows.

The timer T includes conventional cams t1, t2, t3 and t4 for operating the various components, also in the control box, to be described. The timer T is set by a control knob K on the side of the control box.

As FIG. 4 shows, in timer T the cam t1 controls energization of pump contactor coil 50 ofa contactor 52 for operating motor PM for pump P; cam 12 controls energization of the solenoids 19 and 21a for the mix valve 18 and the hot valve 21, respectively; cam t3 controls energization of the regulating valve solenoid Me; and cam 14 controls energization of time motor TM. Energization of timer motor TM is also controlled by pressure switch PS, as hereinafter explained. An on-off toggle switch 51 is provided, as well as a conventional ac power source comprising supply lines L1, L2 and N.

The extension 13 of chamber C also has a nipple 15 between openings 40 and 41 and the passage 16 of the tank is in fluid communication, via conduit 17, with the nipple 15 and chamber C.

Thus, the general flow of fluid is from the supply spigots not shown), through a mixer valve 18 (operated by a solenoid 19), and down a liquid feeder tube 20 into the chamber C. Water from the hot water line 4 can also be diverted (as will later appear) by a hot water valve 21, operated by solenoid 21a, into ajar 210 of detergent and this water picks up the detergent and carries it via tube 21b into the feeder tube 20, and consequently the chamber C and tank 6. The detergent is used for the second cycle, namely the washing cycle, as will appear, and jar 210 may be filled manually by releasing the bail handle 21d (FIG. 1), or by automatically timed means (not shown).

It should be noted that the height of the regulating chamber C is set relative to tank 6 being cleaned so that the fluid level in the tank is regulated to, that is the same as, the level of the fluid in chamber C.

The fluid level is controlled or regulated by the level of the fluid in chamber C. Therefore, height of the chamber inlet 15 is about 4 to 8 inches lower than tank outlet 16. For example, assuming the stopper 42 is down and thus closes the discharge outlet 40 of the chamber, the level of the fluid in the chamber C is controlled by a normally closed pressure switch 22, which switch causes closing of the solenoid operated water valve. The switch 22 is actuated by the height of the fluid in a pressure tube 23 extending from the pressure switch downwardly into the chamber. The switch 22 regulates the water valves and consequently the flow of the water to chamber C. The extent to which the pressure tube extends into the chamber determines the height to which the chamber will fill, and this setting need not be adjusted.

An example of a typical cycle of operation is as follows. Assume that unit U and tank 6 are connected, as shown in FIGS. 1 and 2; that on-off toggle switch 51, shown in FIG. 4, is closed; that the hot and cold water hoses 3 and 4 are being charged with water; and that chamber C is empty.

In order to start the cycle, the cams tl and t2 must be in a position wherein coil 50 of contactor 52 is connected to contact PS3 of pressure switch 22 and wherein solenoid coil 19 of mix valve 18 is connected to contact PS2 of pressure switch 22. Normally, the cams t1 and t2 assume this position when control knob K of timer T is turned to on position. At this point, cam t3 assumes a position wherein solenoid coil Me is deenergized and, therefore, regulating chamber drain opening 40 is closed by stopper 42 and tank drain opening 41 is open. At this point cam t4 assumes a position wherein timer motor TM is not connected directly to line L1. Since chamber C is empty (any water therein having drained out through hole 44), pressure switch 22 connects its contact PS1 to contact PS2 and solenoid 19 for mix valve 18 is energized.

With mix valve 18 open, clean water (at a temperature of F, for example, for cleaning milk from tank 6) enters chamber C and begins to fill it to line F1. When the water rises to line Fl, pressure switch 22 operates to disconnect its contact PS1 from contact PS2 and to connect contact PS1 to contact PS3 with the following results: solenoid 19 deenergizes and closes mix valve 18 thereby stopping water flow into chamber C; contactor coil 50 energizes to close contactor 52 and starts pump motor PM and pump P driven thereby; and timer motor TM is energized and begins to drive all of its four cams.

With pump P in operation, rinse water is pumped from chamber C through hoses 10 and 5 into tank 6. From tank 6, the rinse water drains through hose 17 and out tank drain opening 41 which is open. When the water level in chamber C is pumped down to level F3, pressure switch 22 operates to disconnect its contact PS1 from contact PS3 and to connect contact PS1 to contact PS2 with the following results solenoid 19 energizes to open mix valve 18 to again start water flow into chamber C; contactor coil 50 deenergizes to open contactor 52 and stops pump P; and timer motor TM is deenergized and stops driving its cams.

The foregoing operation, wherein the chamber C is alternately filled and emptied several times, may be referred to as the spin-burst portion of the first rinse cycle and occurs during the first minute, for example, of the cycle, as FIG. 5 shows. During this first minute, timer motor TM is energized several times and finally drives its four cams into a condition wherein cam t4 maintains timer motor TM connected to line L1, while the other three cams cause their contacts to open. Timer T thus starts to run for about five minutes, for example, for the remainder of the first rinse cycle, during which time tank 6 is permitted to drain completely before the detergent wash cycle. This time delay also allows for hot water tank recovery.

When the timer T advances to the fill position for the wash cycle, since pressure switch contact PS1 engages contact PS2, cam t2 effects energization of solenoid 21a to open hot water valve 21 and cam [3 effects energization of solenoid Me to close tank drain opening 41 and open regulating chamber drain opening 40. Hot water then flows through hose 4, valve 21, detergent jar 21c, hose 21b and hose into chamber C and from there through opening 40 and hose 17 to tank 6. When tank 6 and chamber C are filled to the level F1 (in FIG. 1), which takes about 1 minute, pressure switch 22 operates to disconnect contact PS1 from contact PS2 and to connect its contact PS1 to contact PS3. As a result, hot water valve 21 closes to shut off the hot water and timer motor TM starts to operate. After about 1 minute of timer operation the timer cam [1 effects operation of pump P, cam t3 maintains solenoid 142 of the regulating valve energized, and cam t4 maintains energization of timer motor TM. During the wash cycle, which lasts for about ten minutes, as FIG. 5 shows, hot water with detergent therein is recirculated by pump P through tank 6 to cleanse the tank.

At the end of this ten minute cycle, timer T has operated its cams so that cam 11 causes pump P to stop and cam t3 causes tank drain opening 41 to open and regulating chamber drain opening 40 to close. Cam t4 maintains timer motor TM in operation. The last three minutes, for example, of the wash cycle, as FIG. 5 shows, is an extended drain period during which all detergent water is allowed to drain from tank 6, through hose l7.

Timer T then advances to the second rinse cycle, whereat during the first minute, intermittent operation of timer motor TM is controlled by pressure switch 22 instead of by cam 14. During the first minute of the second rinse cycle, the pressure switch 22 effects intermittent operation of pump P as the regulating chamber alternately fills and drains to provide spin-burst rinsing of tank 6 as during the first minute of the first rinse cycle hereinbefore described.

During the remainder of the second rinse cycle, which lasts about nine minutes, for example, cam t4 maintains timer motor TM in operation so that the timer T can advance to its off position. During the remainder of the second rinse cycle the regulating chamber C drains through opening 44 and tank 6 drains through hose 17 and tank drain opening 41. The tank 6 is now completely washed and rinsed.

As FIG. 5 shows, after the timer T is in off position, the unit is ready to operate in the sanitize cycle. In common practice among dairymen, the sanitize cycle is used just prior to the time that tank 6 is to be filled with milk. The sanitize cycle proceeds as follows. Control knob K is advanced manually by the operator to cause cam t3 to energize regulating valve solenoid 14e (thereby closing tank drain opening 41 and opening regulating chamber drain opening 40) and to cause cam 12 to energize solenoid 19 (thereby opening mix valve 18). Clean F water then enters regulating chamber C and starts to backfill tank 6 from regulating chamber C through hose 17. As this occurs, a desired amount of a suitable sanitizing agent (or mineral removal agent) may be poured into the open top of regulating chamber C by the operator. When chamber C is filled to level Fl, pressure switch 22 causes its contact PS1 to disengage from contact PS2 and engage contact PS3. This, in turn, causes timer motor TM to operate and drive the timer cams to positions wherein cam t1 effects operation of pump P, cam t2 energizes solenoid 19 to maintain the mix valve 18 open, cam t3 energizes solenoid Me of the regulating valve to maintain drain opening 40 open and tank drain opening 41 closed, and cam t4 energizes the timer motor TM. This portion of the sanitize cycle is similar to the wash cycle, except that the mix valve 18 is open instead of the hot water valve 21 during one minute of the cycle. Pump P recirculates sanitized water from chamber C, through hose 5, tank 6 and hose 17, back to chamber C. As FIG. 5 shows, at the end of the second minute of the sanitize cycle, mix valve 18 closes, and recirculation of sanitized water continues for about 4 minutes. At the end of this interval, timer motor TM causes cam 11 to deenergize pump P and cam 13 to deenergize regulating valve solenoid 14e, thereby closing drain 40 and opening tank drain 41. Tank 6 is thus able to drain through hose 17 and drain 41 and timer T advances to its final off position, as FIG. 5 shows.

Referring again to the nozzle N, it includes a hollow spinner 30 having a series of holes 31 extending through its cylindrical wall so that a high velocity spray issues from the rotating nozzle and circulates water and detergent to all parts of the tank interior.

The spinning nozzle N, which is driven by the water being forced therefrom under pressure, insures that the water completely cleans the interior of the tank, US. Pat. No. 3,448,742, hereinbefore referred to, discloses a spinner nozzle suitable for use in the present invention.

I claim:

1. A portable and automatic washing unit for tanks comprising a support frame, an electric motor driven fluid pump carried on said frame, a fluid regulating chamber carried on said frame, said chamber comprising means forming a regulating chamber drain opening near the bottom thereof, means forming a hollow extension therebelow comprising means forming a tank drain opening near the bottom thereof, means forming a first fluid port in said chamber above said regulating chamber drain opening, and means forming a second fluid port in said extension intermediate of said drain openings, conduit means connected at one end to the discharge of said pump and having a free end adapted to be placed in a tank to be cleaned, a second conduit connected at one end to the inlet of said pump and at the other end to said first fluid port of said regulating chamber, a third conduit connected at one end to said second fluid port in said extension at the lower portion of said chamber and its other end being connectible to the lower portion of said tank. both third conduit connections being at a level whereby fluid drains between said chamber and tank to regulate the fluid level within said tank, said chamber also having means forming a drain outlet, drain stopper means including a solenoid operated regulating chamber drain stopper and a tank drain stopper engageable with said regulating chamber drain opening and said tank drain opening, respectively, and mounted for shifting between raised position wherein said regulating chamber drain is open and said tank drain'is closed and lowered position wherein said regulating chamber drain is closed and said tank drain is open; electrical control means including an electric timer, a solenoid operated water supply valve, a water supply conduit connected to said water supply valve for supplying water to said chamber and consequently to said tank, water level regulating means extending into said chamber and including a pressure switch responsive to water levels in said chamber, and stopper solenoid means for raising said drain stopper means, said control means being operative to sequence the operation of said water supply valve, said pump, said timer, said stopper solenoid means, and said pressure switch.

2. The combination of claim 1 further characterized in that said water level regulating means includes a pressure tube extending into said chamber to sense the water level therein.

3. A unit as defined in claim 2 including a rotatable nozzle on said free end of said conduit means in said tank, said nozzle being rotatable by water passing therethrough to thoroughly clean the inside of said tank.

4. The combination defined in claim 1 further characterized in that said drain stopper means includes a rod for connection with said stopper solenoid means, said drain stoppers being mounted on said rod.

5. A unit as defined in claim 4 including a rotatable nozzle on said free end of said conduit means in said tank, said nozzle being rotatable by water passing therethrough to thoroughly clean the inside of said tank.

6. A unit as defined in claim 1 including a rotatable nozzle on said free end of said conduit means in said tank, said nozzle being rotatable by water passing therethrough to thoroughly clean the inside of said tank.

7. A unit as defined in claim 1 wherein said timer functions to connect said valve and said electric motor driven fluid pump to said pressure switch for alternative operation thereby during at least a portion of the operating cycle of said unit to effect periodic bursts of water from the free end of said conduit means into said tank.

8. A unit as defined in claim 7 including a rotatable nozzle on said free end of said conduit means in said tank, said nozzle being rotatable by water passing therethrough to clean the inside of said tank by a spinburst action. 

1. A portable and automatic washing unit for tanks comprising a support frame, an electric motor driven fluid pump carried on said frame, a fluid regulating chamber carried on said frame, said chamber comprising means forming a regulating chamber drain opening near the bottom thereof, means forming a hollow extension therebelow comprising means forming a tank drain opening near the bottom thereof, means forming a first fluid port in said chamber above said regulating chamber drain opening, and means forming a second fluid port in said extension intermediate of said drain openings, conduit means connected at one end to the discharge of said pump and having a free end adapted to be placed in a tank to be cleaned, a second conduit connected at one end to the inlet of said pump and at the other end to said first fluid port of said regulating chamber, a third conduit connected at one end to said second fluid port in said extension at the lower portion of said chamber and its other end being connectible to the lower portion of said tank, both third conduit connections being at a level whereby fluid drains between said chamber and tank to regulate the fluid level within said tank, said chamber also having means forming a drain outlet, drain stopper means including a solenoid operated regulating chamber drain stopper and a tank drain stopper engageable with said regulating chamber drain opening and said tank drain opening, respectively, and mounted for shifting between raised position wherein said regulating chamber drain is open and said tank drain is closed and lowered position wherein said regulating chamber drain is closed and said tank drain is open; electrical control means including an electric timer, a solenoid operated water supply valve, a water supply conduit connected to said water supply valve for supplying water to said chamber and consequently to said tank, water level regulating means extending into said chamber and including a pressure switch responsive to water levels in said chamber, and stopper solenoid means for raising said drain stopper means, said control means being operative to sequence the operation of said water supply valve, said pump, said timer, said stopper solenoid means, and said pressure switch.
 2. The combination of claim 1 further characterized in that said water level regulating means includes a pressure tube extending into said chamber to sense the water level therein.
 3. A unit as defined in claim 2 including a rotatable nozzle on said free end of said conduit means in said tank, said nozzle being rotatable by water passing therethrough to thoroughly clean the inside of said tank.
 4. The combination defined in claim 1 further characterized in that said drain stopper means includes a rod for connection with said stopper solenoid means, said drain stoppers being mounted on said rod.
 5. A unit as defined in claim 4 including a rotatable nozzle on said free end of said conduit means in said tank, said nozzle being rotatable by water passing therethrough to thoroughly clean the inside of said tank.
 6. A unit as defined in claim 1 including a rotatable nozzle on said free end of said conduit means in said tank, said nozzle being rotatable by water passing therethrough to thoroughly clean the inside of said tank.
 7. A unit as defined in claim 1 wherein said timer functions to connect said valve and said electric motor driven fluid pump to said pressure switch for alternative operation thereby during at least a portion of the operating cycle of said unit to effect periodic bursts of water from the free end of said conduit means into said tank.
 8. A unit as defined in claim 7 including a rotatable nozzle on said free end of said conduit means in said tank, said nozzle being rotatable by water passing therethrough to clean the inside of said tank by a spin-burst action. 